Image forming apparatus and developer supply method

Abstract

An image forming apparatus of the present invention includes a developing device. In a case body of the developing device, a first storage chamber and a second storage chamber are formed. A first agitating screw is provided in the first storage chamber and a second agitating screw is provided in the second storage chamber. A developing roller is provided in the second storage chamber. A control portion controls driving of a first motor and a second motor. When toner installation is performed, the control portion controls driving of the first motor at a rotational speed higher than a rotational speed for development operation in a state where the second motor is stopped. When a certain condition is satisfied, the control portion starts control of driving of the second motor, to drive rotation of the second motor.

The invention claimed is: 
     
       1. An image forming apparatus comprising:
 a developing device having a storage chamber in which developer is stored; 
 a supply portion, provided in the developing device, configured to guide, into the storage chamber, the developer supplied from outside; 
 a developing roller, provided in the storage chamber so as to be rotatable, configured to contact with the developer stored in the storage chamber to hold the developer on an outer circumferential surface by the developing roller being driven to rotate; 
 a conveying member, provided in the storage chamber so as to be rotatable, configured to convey the developer supplied from the supply portion, from one end, in an axial direction, of the developing roller to the other end by the conveying member being driven to rotate; 
 a first driving portion configured to drive the developing roller so as to rotate; 
 a second driving portion configured to drive the conveying member so as to rotate; 
 a driving control portion configured to control driving of the first driving portion in a state where the second driving portion is stopped until the developer is conveyed to the other end by the conveying member, in a case where the developer is supplied from the supply portion into the storage chamber that is vacant, and to start control of driving of the second driving portion on the condition that the developer has been conveyed to the other end; and 
 an obtaining portion configured to obtain information representing a production time of the developer to be supplied from the supply portion, wherein 
 the driving control portion determines a second rotational speed that is lower than a first rotational speed at which the developing roller is driven to rotate during development by the developing device, according to an elapsed time, after production, which is calculated based on the production time, and starts control of driving of the second driving portion such that the developing roller rotates at the second rotational speed having been determined. 
 
     
     
       2. The image forming apparatus according to  claim 1 , wherein the driving control portion controls driving of the second driving portion such that the developing roller rotates at the second rotational speed until the developing roller rotates a preset number of times
 that is higher than a third rotational speed at which the conveying member is driven to rotate during development by the developing device, until the developer is conveyed to the other end. 
 
     
     
       3. The image forming apparatus according to  claim 1 , wherein the driving control portion controls driving of the first driving portion such that the conveying member rotates at a fourth rotational speed that is higher than a third rotational speed at which the conveying member is driven to rotate during development by the developing device, until the developer is conveyed to the other end. 
     
     
       4. The image forming apparatus according to  claim 1 , wherein the driving control portion determines the second rotational speed such that the shorter the elapsed time is, the lower the second rotational speed with respect to the first rotational speed is, and the longer the elapsed time is, the higher the second rotational speed with respect to the first rotational speed is. 
     
     
       5. An image forming apparatus comprising:
 a developing device having a storage chamber in which developer is stored; 
 a supply portion, provided in the developing device, configured to guide, into the storage chamber, the developer supplied from outside; 
 a developing roller, provided in the storage chamber so as to be rotatable, configured to contact with the developer stored in the storage chamber to hold the developer on an outer circumferential surface by the developing roller being driven to rotate; 
 a conveying member, provided in the storage chamber so as to be rotatable, configured to convey the developer supplied from the supply portion, toward the developing roller, by the conveying member being driven to rotate; 
 a first determination portion configured to determine that the developer conveyed by the conveying member has reached the developing roller; 
 a driving portion configured to drive at least the developing roller so as to rotate; and 
 a driving control portion configured to control driving of the driving portion such that the developing roller rotates at a predetermined fifth rotational speed in a case where the developer is supplied from the supply portion into the storage chamber that is vacant, and to control driving of the driving portion such that the developing roller rotates at a sixth rotational speed lower than the fifth rotational speed on the condition that the first determination portion determines that the developer has reached the developing roller. 
 
     
     
       6. The image forming apparatus according to  claim 5 , further comprising a second determination portion configured to determine that the developer conveyed by the conveying member is held over an entirety of the outer circumferential surface of the developing roller, wherein
 the driving control portion controls driving of the driving portion such that the developing roller rotates at the sixth rotational speed until the second determination portion determines that the developer is held over the entirety of the outer circumferential surface of the developing roller. 
 
     
     
       7. The image forming apparatus according to  claim 6 , wherein the second determination portion makes determination based on one of a number of times the developing roller rotates at the sixth rotational speed, a measured value from a measurement portion that measures a charge amount of the developing roller, and a sensor signal from a density sensor that detects a density of the developer in the storage chamber. 
     
     
       8. The image forming apparatus according to  claim 5 , further comprising an obtaining portion configured to obtain information representing a production time of the developer to be supplied from the supply portion, wherein
 the driving control portion determines the sixth rotational speed according to an elapsed time, after production, which is calculated based on the production time, and controls driving of the driving portion such that the developing roller rotates at the sixth rotational speed having been determined. 
 
     
     
       9. The image forming apparatus according to  claim 8 , wherein the driving control portion determines the sixth rotational speed such that the shorter the elapsed time is, the lower the sixth rotational speed with respect to the fifth rotational speed is, and the longer the elapsed time is, the higher the sixth rotational speed with respect to the fifth rotational speed is. 
     
     
       10. The image forming apparatus according to  claim 5 , wherein the fifth rotational speed is a speed at which the developing roller is driven to rotate during development by the developing device. 
     
     
       11. The image forming apparatus according to  claim 5 , wherein the first determination portion makes determination based on one of a number of times the conveying member rotates, a measured value from a measurement portion that measures a charge amount of the developing roller, and a sensor signal from a density sensor that detects a density of the developer in the storage chamber. 
     
     
       12. A developer supply method for supplying developer into a storage chamber in a state where the storage chamber is vacant without storing the developer, the developer supply method being performed by an image forming apparatus that includes: a developing device having the storage chamber in which the developer is stored; a supply portion, provided in the developing device, configured to guide, into the storage chamber, the developer supplied from outside; a developing roller, provided in the storage chamber so as to be rotatable, configured to contact with the developer stored in the storage chamber to hold the developer on an outer circumferential surface by the developing roller being driven to rotate; a conveying member, provided in the storage chamber so as to be rotatable, configured to convey the developer supplied from the supply portion, from one end, in an axial direction, of the developing roller to the other end by the conveying member being driven to rotate; and an obtaining portion configured to obtain information representing a production time of the developer to be supplied from the supply portion, the developer supply method comprising;
 a first step of driving the conveying member so as to rotate, and causing the conveying member to convey the developer to the other end in a state where rotation of the developing roller is stopped; and 
 a second step of starting driving of rotation of the developing roller on the condition that the developer has been conveyed to the other end, wherein 
 in the second step, a second rotational speed that is lower than a first rotational speed at which the developing roller is driven to rotate during development by the developing device, is determined according to an elapsed time, after production, which is calculated based on the production time, and control of driving of the second driving portion is started to rotate the developing roller at the second rotational speed having been determined. 
 
     
     
       13. A developer supply method for supplying developer into a storage chamber in a state where the storage chamber is vacant without storing the developer, the developer supply method being performed by an image forming apparatus that includes: a developing device having the storage chamber in which the developer is stored; a supply portion, provided in the developing device, configured to guide, into the storage chamber, the developer supplied from outside; a developing roller, provided in the storage chamber so as to be rotatable, configured to contact with the developer stored in the storage chamber to hold the developer on an outer circumferential surface by the developing roller being driven to rotate; a conveying member, provided in the storage chamber so as to be rotatable, configured to convey the developer supplied from the supply portion, toward the developing roller, by the conveying member being driven to rotate; and a driving portion configured to drive at least the developing roller so as to rotate, the developer supply method comprising;
 an eleventh step of controlling driving of the driving portion such that the developing roller rotates at a predetermined fifth rotational speed when the developer is supplied from the supply portion; 
 a twelfth step of determining that the developer conveyed by the conveying member has reached the developing roller; and 
 a thirteenth step of controlling driving of the driving portion such that the developing roller rotates at a sixth rotational speed lower than the fifth rotational speed on the condition that the developer is determined in the twelfth step as having reached the developing roller.